1. Field of the Invention
Construction blocks are manufactured independently or in place for final use using materials generally considered to be discardable or of limited value. The stones and/or coarse aggregate material is placed in molds in intimate, abutting contact, then concrete, mortar or other binder is poured in to securely hold the material in place forming the block. Other strata of different composition and/or tubes and reinforcement can be included.
2. Description of Related Art
Conventionally, concrete is defined in terms of its specific materials, strength, and design. Concrete generally used as a structural component consists of cement with fine and/or coarse aggregates that have adjusted granule sizes.
The term “rich concrete” usually refers to a product of mixed cement and aggregate, that often includes an iron reinforcement. Among aggregates for “rich concrete,” sea sand is used as a fine aggregate but earth and sand are becoming scarce in view of forestation and other conservation activities. The collection of sea sand has been forbidden in many places because of its limited reserves and significant adverse influence on the environment and deep sea ecosystems. Large scale mining for limestone, which is largely demanded as raw material for cement, results in changing mountain and landscape appearance. This mining results in ecological, scenic and energy consumption that does harm to the environment. It also leads to resource depletion and environmental pollution due to the spreading of industrial waste.
Conventional block or discrete structures include stone arch bridges. Although there are some structural similarities, traditional discrete techniques assume the use of high quality stones that are generally inordinately or excessively large in strength when designed. Design quality is dependent on the skill of stonemasons while the technique according to the present invention emphasizes sound design and reliable practice.
Stone arch bridges are conventionally not considered to be a modern construction technique although their arch, beauty and harmony with nature are well recognized. Among many, the following reasons are practically given for this:    (1) Stone bridges have low load-bearing capacity and are an old style used primarily for pedestrians;    (2) Only short spans are considered safe for stone bridges;    (3) Stone materials are not uniform and are considered vulnerable to earthquakes;    (4) Discrete structure does not provide for a quantitative evaluation for safety and unit stress;    (5) Appearance depends on the skill of traditional stonemasons, who are now very few; and    (6) Stone bridges require high construction cost.
The prior art technologies can be categorized by (1) whether low quality material can be used for main structural components or not, (2) whether it is a discrete structure or not, and (3) whether it is an arch or not. The technique using low quality materials is not recognized as a modern technique.
To date, it has been believed that discrete structures are vulnerable to earthquakes. This is because brick buildings were seriously damaged in Kanto's big earthquake. Since then, arch structures have been considered the same as brick buildings.